Tuesday, May 15, 2012

New paper finds large increase in sunshine since the 1980's; dwarfs alleged effect of CO2

A paper recently published in the journal Weather finds that global summer average sunshine [solar short-wave radiation that reaches Earth's surface] dimmed during the period 1958-1983 [prompting an ice age scare], but markedly increased from 1985-2010. The increase in summer average sunshine between those two periods is 6 Watts per square meter, which dwarfs the alleged effects of CO2 by more than 5 times. [Alleged CO2 effect from 1958-2010 was calculated using the IPCC formula 5.35*ln(389.78/315) = 1.14 Watts per square meter]. At one measurement site [De Bilt], summer sunshine increased from 1985-2010 by 15 Watts per square meter, more than 23 times the IPCC alleged forcing from CO2 during the same timeframe [5.35*ln(389.78/346.04) = 0.64 Watts per square meter].

The paper states the increase in sunshine reaching the Earth's surface is due to a decrease in aerosols including clouds, which are influenced by both anthropogenic and natural factors, and possibly changes in solar activity.

- The paper is based on data from two sites in the Netherlands, 45km apart.- The authors make no claims about global anything. When the paper talks about "surface global short-wave radiation," they're talking about the sum of the direct and diffuse radiation at their two sites, not what's happening around the world. - The paper says that, because of reduced aerosols, it's gotten sunnier and hotter in the Netherlands. At least during the summer daytimes.- There's actually a warming trend over the whole period examined, which includes the pre-breightening period, so... there's other stuff going on. Like "the anthropogenic greenhouse effect," according to the authors.- The forcings mentioned are apples-oranges with global CO2 forcing. Differences include: these are local measures, not global; the 15 W/m2 was for summers only; and it's measuring only the difference in incoming short-wave radiation, not the total net forcing. The units are the same, but they are different things (if I count the red M&Ms, and you count all colors, we're both counting M&Ms, but are talking about different numbers; saying that your count is bigger than mine doesn't mean much).

In short: this is an interesting paper. But it doesn't say anything about climate change (apoart from implying that increases in aerosols in e.g. China would lead to reduced warming). I'm not sure why "skeptics" are trumpeting it. It doesn't say anything that's inconsistent with standard climate science.

"Standard" climate science includes claims of accelerating increases in global temperatures. So where's the acceleration? Not only is their no acceleration but we've been essentially flat for about a decade now. No "dramatic" increase but instead just what appears to be natural cycles.

"Standard" climate science only looks at TSI, ignores marked changes in UV within and between solar cycles, and concludes the Sun has nothing to do with climate change, despite amplification mechanisms via ozone and possibly cosmic rays. Solar UV is what heats the oceans, not GHGs

"Standard" climate science assumes clouds and water vapor act as a positive feedback, despite considerable evidence they cause negative feedback, including the fact this planet hasn't incinerated over the past 4.5 billion years.

The paper is not measuring "incoming short wave radiation" It is measuring the total net forcing at Earth's surface- "sunshine" -incoming from the Sun minus changes in albedo.

The forcing comparison in the post is not apples/oranges and serves to demonstrate the claim of "standard" climate science that there is no other explanation for global warming other than increased CO2 is a fallacy.